Inductors are common electrical circuit elements implemented within wireless communication devices and a wide range of other electronic devices. Although inductors are very useful and desirable, they are often one of the most space-consuming elements of a radio frequency integrated circuit (RFIC). In an RFIC, inductors are commonly used within amplifier elements of the RFIC component commonly referred to as the “mixer.” A mixer generally refers to the portion of an RFIC which generates (i.e., mixes) a baseband signal from a received carrier waveform. Mixers are also used on the transmitter side, e.g., to modulate a baseband signal onto a carrier.
On the receiver side, the mixer receives a waveform, which typically includes a carrier wave modulated with a baseband data signal. The mixer may include an amplifier element to properly tune the received waveform. The mixer synthesizes a copy of the carrier wave, e.g., using a local oscillator (LO) of the device. The mixer then removes the baseband signal from the received waveform by essentially subtracting the carrier wave generated by the LO from the received waveform. Once removed from the carrier, the baseband signal can then be converted into digital samples and demodulated, e.g., by a digital circuit.
An inductor may be used within the amplifier element of the mixer in order to set the performance of the mixer to a particular operating frequency. Some wireless communication devices support multiple frequency bands, in which case, multiple mixers are typically needed. Moreover, each mixer requires its own inductor to set its performance at the operation frequency associated with the respective mixer. The use of several different mixers to support multiple frequency bands is undesirable, particularly due to the space consumption that would be required within the RFIC to accommodate the different inductors.